The impact of lateral carbon fluxes on the European carbon balance

Abstract. To date, little has been written about the important role played by processes transporting carbon laterally over continents, and from continents to oceans. These processes have an impact on the CO2 budgets and on the carbon budgets at local, regional and continental scales. We estimated the impact on the European carbon balance of the transport of carbon by the trade of wood and food products, by the emission and oxidation of reactive reduced carbon species, and by rivers and freshwater systems up to estuaries. The analysis is completed by new estimates of the carbon fluxes of coastal seas. The magnitude of the CO2 and carbon fluxes caused by lateral transport over Europe is comparable to current estimates of carbon gain by European ecosystems. At the continental level, we estimate a CO2 sink over Europe of 140 TgC yr−1 and a carbon sink of 50 TgC yr−1 being caused by lateral transport processes.